Answer:
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It's a chemical change because it's changing the object's property.
Answer:
Explanation:
1)<u> Convert the distance, 13.1 km to miles</u>
1 = 1 mi / 1.61 km
- 13.1 km [ 1 mi / 1.61 km ] = 8.1336 mi
2)<u> Use 6.2 mi/h as a converstion factor between distance and time</u>
- 8.1366 mi × 1 / [6.2 mi/h] = 1.3124 h
3) <u>Convert 1.3124 h to minutes</u>
- 1.3124 h × [ 60 min/h] = 78.7 min
Rounding to the nearest minutes (two significant figures):
Answer:
27.60 g urea
Explanation:
The <em>freezing-point depression</em> is expressed by the formula:
In this case,
- ΔT = 5.6 - (-0.9) = 6.5 °C
m is the molality of the urea solution in X (mol urea/kg of X)
First we<u> calculate the molality</u>:
- 6.5 °C = 7.78 °C kg·mol⁻¹ * m
Now we<u> calculate the moles of ure</u>a that were dissolved:
550 g X ⇒ 550 / 1000 = 0.550 kg X
- 0.84 m = mol Urea / 0.550 kg X
Finally we <u>calculate the mass of urea</u>, using its molecular weight:
- 0.46 mol * 60.06 g/mol = 27.60 g urea
Answer-Figure P38.63a
is a three-dimensional sketch of a birefringent crystal. The dotted lines illustrate how a thin, parallefaced slab of material could be cut from the larger specimen with the crystal’s optic axis parallel to the faces of the plate.”
Sorry if it’s it correct
